Contact apparatuses of this kind are well-known from the DE-PS No. 25 27 681 and the DE-AS No. 14 65 090. There, the segmented body is formed by a--e.g. cylindrically curved or rolled--metal strip having the flexibility of a spring and being made of an electrically conductive material or having a sheath made of such a material. The bar-like strip sections remaining between the slots form the contact segments having a curved shape and protruding from the surface of the metal strip or the cylinder respectively. At their peak area, the contact segments enter into electrically conductive pressure contact with one of the contact bodies whilst the same kind of contact occurs between the other contact body and the end areas of the contact segments extending on both sides thereof or the edge zones in these end areas respectively, in order to guarantee a reliable contact making with small electrical transfer resistance. A contact force in the peak area causes the appearance of a couple of reaction contact forces of half the magnitude of said peak-located contact force at both corresponding points of contact in the edge zones.
In numerous applications, these well-known contact apparatuses function satisfactorily. However, in the case of a high contact current load and especially of frequent closing and opening operations, the use of such apparatuses causes the following problems:
Under the influence of the contact force F defined points of contact are in any case formed in the peak area of the segments whilst the points of contact in the edge zones on both sides are more or less undefined because of the contact with the corresponding contact body on a comparatively big surface. Thus, it may occur that, for several contact segments, only one single point of contact exists in each of said edge zones, having a comparatively small current-carrying contact surface and being therefore charged by an excessive current density and possibly an excessive transfer resistance as well.
In addition, the well-known apparatuses show an increased predisposition to mechanical abrasion if the plugging and separating process of contact bodies having the form of sockets and plugs takes place, especially in case of mechanical actuation of these contact bodies. It should be noted that the points of contact at the peak of the contact segments glide alongside the same line on the surface of the contact body if there is a relative motion of the contact bodies towards each other. The abrasion of the surface, often coated with a special contact material, concentrates therefore on these areas of the surface, what may lead to a premature destruction of the surface structure and, consequently, may create the conditions for the formations of oxide layers and the superheating of the contact apparatus as well.